Donepezil, also known as Aricept™, or 2-((1-benzylpiperidin-4-yl)methyl)-5,6-dimethoxy-2,3-dihydro-1H-inden-1-one, is a centrally acting reversible acetylcholinesterase (AChE) inhibitor. Its main therapeutic use is in the treatment of Alzheimer's disease where it is used to increase levels of cortical acetylcholine. See US FDA label for Aricept @http://www.accessdata.fda.gov/drugsaifda_docs/label/2006/020690s026,021720s003lbl.pdf Donepezil is currently approved for treatment of Alzheimer's disease. Despite the beneficial activities of donepezil, there is a continuing need for new compounds to treat Alzheimer's diseases and conditions. It is desirable to discover novel derivatives thereof. Donepezil is described in U.S. Pat. Nos. 4,895,841 and 7,727,548, the contents of which are incorporated herein by reference.